1. Field of the Invention
The present invention pertains to the art of cooking appliances and, more particularly, to operating various heating devices in a cooking appliance to maintain a selected temperature and, if no cooking operation is initiated for a predetermined period of time, automatically lowering the selected temperature to conserve energy.
2. Discussion of the Prior Art
In general, it is known to combine various heating techniques to establish a particular temperature in a cooking appliance. That is, once a particular cooking temperature is selected and input into the appliance by a consumer, the various heating techniques are operated singly or in combination to heat an oven cavity to achieve the selected temperature. In many cases, during an initial pre-heat mode, the heating devices are operated at full power to achieve the selected temperature in a short period of time. After the selected temperature has been achieved, the heating devices are thereafter operated so as to maintain the selected temperature in the oven cavity. More specifically, the heating devices are again operated singly or in various combinations to maintain the temperature in the oven cavity between predetermined, upper and lower temperature limits established based on the selected temperature.
If the cooking operation is not started within a short period of time after completion of the pre-heat mode, a considerable amount of energy is wasted in order to maintain the oven cavity at the selected temperature. That is, if a consumer becomes distracted or, for whatever reason, cannot start cooking, the oven will continue to operate the heating devices in an effort to maintain the selected temperature indefinitely. In a commercial environment, often times the oven is started early and then used only periodically during the day. That is, in order to avoid the time delay associated with pre-heating the oven cavity, the oven is typically turned on at the beginning of daily operations and not shut off until the end of the day. Even though the oven may only be used periodically during a given shift, it would be impractical to turn the oven on and off, as the delay required for pre-heating the oven would delay the preparation and presentation of meals to the consumer. Therefore, particularly in commercial environments, a great deal of energy is lost maintaining the cooking appliance at the selected temperature.
Based on the above, there exists a need in the art for a cooking appliance that operates in a manner so as to conserve energy. More specifically, there exists a need for an appliance that controls operation of various heating elements in order to establish a selected temperature for an oven cavity and, if no cooking operation is initiated for a predetermined period of time, automatically reduces operation of the heating elements to conserve energy.